The overall objective of the research proposed in this application is to evaluate in a quantitative manner the program of protein synthesis during growth and meiotic maturation of the mammalian oocyte. Such information is fundamental to an understanding of the molecular basis of mammalian oogenesis and the contribution of the egg to early embryonic development of the mammal. The selection of the mouse as our primary experimental system will allow us to analyze in vitro a relatively homogeneous population of isolated oocytes, at various stages of growth, in a chemically-defined culture medium which supports their viability and the resumption of melosis in a normal manner. Using experimental biochemical approaches already developed for and/or applied to oogenesis in the mouse in our own laboratory, we will determine the absolute rates of total protein synthesis and the absolute rates of synthesis of specific classes of proteins during oocyte growth and meiotic maturation. These measurements will involve the use of microtechniques for determination of intracellular amino acid pool sizes and rates of protein turnover, "classical" biochemical methods for the isolation of subcellular organelles and proteins, high resolution two-dimensional electrophoresis for analysis of the absolute rates of syntheis of specific proteins, as well as various other methodology. The information obtained as the result of the research proposed in this application will provide a quantitative basis upon which to pursue questions dealing with the control of mammalian oogenesis and embryogenesis at the molecular level.